We’ve been dreaming about knowing Earth’s mantle for decades. Now we finally have a sample

the ship JOIDES DECISION He wanted to say goodbye in a big way. The ship, which was launched in 1978 and which over the past four decades has become one of the most famous scientific drilling ships, Stop counting With support from the National Science Foundation (NSF) in the year 2024. Before that retirement, he participated in a historical geological expedition. Not because of how deep it drilled, but because of what it achieved: a valuable sample of Earth’s mantle that geologists have dreamed of for decades.

The result is relevant as long as we’re chasing after it.

And what can it tell us about our planet.

What happened? Researchers traveling aboard the JOIDES Resolution have yielded an exceptional sample of Earth’s mantle. Thanks to their drilling into the bottom of the Atlantic Ocean, they’ve made tubes and tubes out of material from, mostly, the upper mantle aquamarine, an intrusive igneous rock. “It’s really unusual: more than a kilometer of strongly altered lower crust and/or upper mantle. I would say a mixture,” Andrew Fisher explainsUniversity of California Santa Cruz to Washington Post. In the scientific community, there are those who actually see extraction as “sign” value.

Is it a Guinness hole? The fact is that scientists have made more impressive holes. The Kola missile, as a result of a Soviet test, reached a depth of 12.2 km. And in 2021, a group of well scientists announced that went 8 km Beneath the surface of the Pacific Ocean – yes, tap into the trench – and let him sample in 8060 MB (meters below sea level). If the JOIDES Resolution team has now achieved this success, it is not because of their expertise in seafloor drilling. What really allowed them to hit the jackpot is their accuracy when it comes to choosing where to work.

focused his efforts on Mid-Atlantic mountain rangea mountain range extending mainly under the waters of the Atlantic Ocean up to three kilometers above the ocean floor.

Is this important? Yes, what scientists have been looking for is tectonic window North Atlantic where the drillers didn’t have to dig very deep to get what they were looking for. The reason is simple: because the movement From the oceanic plates, mantle rocks have been pushed toward the surface.

If it is a habit Mohorovicic interruption (Moho), the boundary between Earth’s crust and mantle, is usually located at About 35 kilometers Under the thick continental crust, when we are talking about the oceanic crust, this distance is reduced to seven kilometers and it is less deep if we refer specifically to the mid-Atlantic mountain range.

And where did you get the award? The JOIDES Resolution team collected a sample of Earth rock about a mile deep at the bottom of the North Atlantic Ocean, on a seamount known as Atlantis Massif, located in the “tectonic window” in the middle of the Talentic Ridge. “On Earth, mantle rocks are usually very difficult to access. The Atlantis Massif offers a rare advantage in accessing it, in that it is made up of mantle rocks that have been transported near the surface by the very slow expansion process of the sea below,” Expert explanation.

What is most curious is that the goal of the expedition was not to obtain a huge sample of the mantle. how Journal details SciencesThe team was actually exploring Atlantis for clues to the origin of life, but moved to a place where shallow soundings in 2015 turned up what appeared to be mantle rocks that had been severely altered by the sea. “The drilling magically went well,” Andrew McKeag acknowledgesgeologist at the University of Leeds.

And the reward was…? Treasure in the form of rocks. With their target and a 4,156-foot (1,267-meter) drill, scientists have come up with a sample of Earth’s mantle, which is the core of It is 3280 feet long, which is equivalent to about one kilometer. “It’s a great department,” Fisher accident. Technically, they couldn’t drill the mantle and their well wasn’t a record one, but there are those who have already indicated that the sample they got, which is more than a kilometer long and arranged in cylinders, is. This is how it is referred to For example Biochemist Susan Lang.

The achievement is not simple. After all, six decades ago, in 1961, a group of geologists launched an ocean expedition, known as Project Mohole, that specifically aimed to drill through the thinnest crust on the ocean floor to reach the mantle. What he actually did was open a series of frustrated projects that craved the “jackpot”, Some claim, is now being held by the JOIDES staff. We have fulfilled an ambition that has fueled science communication for decades. McKeague notes.

How was the process? “Unusual”, V.I Campaign words themselves, who acknowledges that while he had hoped to reach mantle rock with “relative ease” due to its location on a mid-Atlantic mountain range, the reality far exceeded any of his expectations. Even the most optimistic.

“Typical expeditions to similar rock formations produce a core about every three hours and usually have a recovery of less than 50%. This mission was unusual: cores were coming out every hour and the recovery was more than 100% on many occasions. The drill was going through the rocks The mantle snakes like butter, and the team reached a final depth of 1,267.8 million cubic feet (meters below the sea floor) after about a month of drilling,” Tells. Margot Godard goes further: “It’s the dream place of geologists.”

What’s up? How the sample was obtained or if it was fairly large is not what really matters in the discovery. What is important is what it can tell us about the depths of our planet, how oceanic crust differs in composition from the upper mantle or how magma melts, flows and separates. This is what scientists hope to solve with JOIDES cylinders.

Another challenge, no less, will be determining how much the rocks represent the mantle. In the end, as Criticize Washington PostMost of this crucial layer of the planet lies beneath the crust, not exposed to the ocean, and questions remain on the table as to whether the materials obtained by JOIDES will allow us to know the mantle or lower crust. In any case, Lang confirms“These are the kinds of rock we’ve been waiting for so long.”

the pictures: 極地狐 (Flickr) f ANZIC-IODP (Twitter), JOIDES resolution (Leslie Anderson)

In Xataka: The Mohole Project: The Crazy, Insane Story of the Deepest Well in History We’ve Ever Drilled